Bestselling author, neuroscientist and sleep expert Matthew Walker reveals five revelatory ways to think about sleep and why you need to start prioritising your shut-eye today.

SleepProfessor Matthew Walker has spent the past 20 years researching sleep and in his latest book, the bestselling Why We Sleep, he investigates the new science of why we sleep and why it’s so integral to every aspect of our health.

The key takeaway? Make sleep your number one priority and you’ll reap so many surprising benefits. Here, Walker reveals four things you never knew about sleep and the central role it plays in our mental and physical health…

1. We’re suffering from a sleep-loss epidemic

According to a survey by research hub Gallup, we sleep on average 25% fewer hours than we did in the 1940s. Walker compares this to surviving on only 75% of the oxygen levels we need to operate. “If that were the case, most humans would be at serious risk, yet we fail to look at sleep in this way.”

Try not to think of sleep as an afterthought – by giving sleep as much priority as your diet and exercise routine, your body and brain will thank you. Sacrificing the odd evening out for a good night’s slumber will pay dividends in the long run.

2. Artificial light is throwing off our natural rhythms

You may have blackout blinds but is your digital clock illuminating the room? Artificial light sources, however small, can make a big difference to our bodies’ internal clock, or circadian rhythm.

“Whether at home or in the office, electric light is not as bright as sunlight, so our brain doesn’t get a clear signal of daytime when we spend time indoors (as so many of us do),” says Walker. “At night the reverse happens – with artificial lighting and street lights, our brains can be confused. As a result, our quality of sleep is jeopardised and we might not feel truly awake during the day.”

To counteract this, spend at least one hour in natural light. You could go for a walk during your lunch break or add extra walking to your commute. At home, invest in an analogue clock that gives off minimal light, or simply cover your digital clock’s display.

3. You can’t force yourself to be a morning person

Forcing yourself to wake up at the crack of dawn when you’re most productive at dusk is futile. According to Walker, you can’t fight biology. “Your chronotype defines whether you are a morning type – a lark – or an evening type – an owl – or somewhere in between. What people don’t realise is that this isn’t a choice; it’s embedded within your genetics. When you’re in sync with your chronotype, your sleep is better and your overall health benefits. The inverse is true if you fight against it.”

If you’re a lark, catch up on that extra work or gym session in the morning. If you’re an owl, set yourself a realistic wake-up time and save exercise or hobbies for lunchtime or after-work. You could even think about discussing flexible working hours with your boss.

4. Sleep trackers may open your eyes

With the rise in new tech, many of us are becoming more empowered when it comes to monitoring the length and quality of our sleep. This can go overboard – ‘orthosomnia’ is a disorder whereby we become obsessed with self-tracking to the point that our sleep suffers. Keeping an eye on your sleep tracker does come with benefits however. “In medicine we commonly say, ‘What gets measured gets managed,’” says Walker.

Once in a while, check your Fitbit or other tracking app to see how your sleep is fairing. Walker suggests that while they’re not always completely accurate, “they give you an indication that something needs to change if you’re going without enough sleep”.

Not getting enough zzz’s could be one reason why you’re not achieving the results you desire from exercising. For seven other surprising reasons, read trainer Emily Cole’s 8 reasons you’re not seeing results in the gym.